Her father, Gilbert Kuypers, spent yesterday morning at the hospital and said because of pain medication his daughter was drowsy and still trying to come to terms with the accident.

"She remembered that she just fell off, and it was just a quick drop, and she only remembers the weightlessness feeling of it, and that was the end of it. She just went blank after that."

Ms Kuypers' colleague had just completed an abseil drop, and when she got over the side of the building and put her weight on the equipment, "the whole lot let go".

Mr Kuypers said, "I'm very confident when she finally gets a bit more out of the pain management that she will be able to recall more of what's happened." He said only a couple of weeks ago she had to be rescued after a piece of her gear malfunctioned and she became stuck mid-abseil.

Since then she had used brand-new equipment, so Mr Kuypers felt the fall was unlikely to have been caused by a gear malfunction. "Maybe the procedures weren't done properly ... the only thing we can say is something obviously has gone wrong.

"Whether it's a systematic error, or a gear failure ..."

A witness to the accident told the Herald a metal anchor which attached Ms Kuypers to the building fell to the ground with her.

The Department of Labour is investigating with the help of Ms Kuypers' employers, At Height, who could not be reached for comment yesterday.

The accident is the third industrial-rope accident in eight months.

A Wellington window washer fell from a building last June and a woman abseiling performance artist plunged 14m down a wall in Auckland's Aotea Square in December.

Mr Kuypers said he would be encouraging his daughter to find a new career.

But he said she was naturally adventurous and credited her fitness from activities such as kayaking and motocross as helping to save her life.

"She's been over the Huka Falls [kayaking] already, twice. So she pushes it a bit."

Ms Kuypers has also landed small parts in television shows including Shortland Street and Go Girls.

Her father said he would eventually visit the Lion building to see just how far Ms Kuypers had fallen, but was amazed she had survived the plunge.

"There must be a lot of angels out there. And I'm sure they work hard."

St John medical director Tony Smith said for Ms Kuypers to survive a four-storey fall was extraordinary.

He said sometimes a harness could slow a fall down, as opposed to an unsupported free fall.

"I don't know whether that was the case or not, but we can say that her survival in terms of the height she fell was extraordinary. And she's a very, very lucky young woman."

Dr Smith said the fact that Ms Kuypers fell in a way that protected her head from major injury was crucial.

An American study of 200 falls showed a person is just as likely to survive a five-storey fall landing feet-first as they are a one-storey fall head-first.

A New York doctor who had dealt with a high number of falls said in 2008 that the death rate from a three-storey fall was about 50 per cent.